Solenoid actuator having misalignment accommodating structure and solenoid valve using the same

Abstract

A solenoid actuator of a solenoid valve has a solenoid, a yoke, a stator, a cup and a restrained portion. The yoke radially surrounds the stator while radially forming an outer circumferential gap therebetween. The cup receives a plunger. The cup is arranged in the stator while radially forming an inner circumferential gap therebetween. The restrained portion is axially inserted between an internal portion of the yoke and the stator. The outer circumferential gap is greater than the inner circumferential gap. Therefore, even when the inner circumferential gap is set to be small to effectively apply magnetic power generated by the solenoid to the plunger, radial misalignment of the cup can be accommodated by the outer circumferential gap.

1. A solenoid actuator comprising:
 a solenoid; 
 a plunger that is arranged substantially coaxially with respect to the solenoid; 
 a stator that has a substantially annular shape defining an inner circumferential face; 
 a cylindrical cup that is arranged radially inside of the inner circumferential face of the stator, the cup receiving the plunger such that the plunger is substantially axially slidable in the cup; 
 a cylindrical yoke that radially surrounds the solenoid and an outer circumference of the stator; and 
 a magnetic force transferring member that is axially inserted between a step portion formed in an inner circumference of the yoke and a radially outer portion of the stator to axially transfer magnetic force between the yoke and the stator, 
 wherein 
 the outer circumference of the stator radially forms a first gap with an inner circumferential face of the yoke therebetween, 
 the inner circumferential face of the stator radially forms a second gap with an outer circumferential face of the cup therebetween, and 
 the first gap is greater than the second gap. 
 
   
   
     2. The solenoid actuator according to  claim 1 , further comprising a bracket that includes:
 a restrained portion that is restrained in the yoke to serve as the magnetic force transferring member; and 
 a fixed portion that externally secures the yoke, 
 wherein the cup includes a collar portion that radially extends outwardly from an outer circumference of the cup, and 
 the collar portion is disposed on an axially opposite side as the solenoid with respect to the restrained portion. 
 
   
   
     3. The solenoid actuator according to  claim 2 , wherein the stator is separated from the bracket. 
   
   
     4. The solenoid actuator according to  claim 1 , wherein the stator, the yoke and the plunger form a magnetic circuit to magnetically attract the plunger. 
   
   
     5. A solenoid valve comprising:
 a solenoid actuator including,
 a solenoid, 
 a plunger that is arranged substantially coaxially with respect to the solenoid, 
 a stator that has a substantially annular shape defining an inner circumferential face, 
 a cylindrical cup that is arranged radially inside of the inner circumferential face of the stator, the cup receiving the plunger such that the plunger is substantially axially slidable in the cup, 
 a cylindrical yoke that radially surrounds the solenoid and an outer circumference of the stator, and 
 a magnetic force transferring member that is axially inserted between a step portion formed in an inner circumference of the yoke and a radially outer portion of the stator to axially transfer magnetic force between the yoke and the stator; and 
 
 a valve body that connects to the plunger, such that the valve body is axially actuated by the plunger to open and close a fluid channel, 
 wherein 
 the outer circumference of the stator radially forms a first gap with an inner circumferential face of the yoke therebetween, 
 the inner circumferential face of the stator radially forms a second gap with an outer circumferential face of the cup therebetween, and 
 the first gap is greater than the second gap. 
 
   
   
     6. The solenoid valve according to  claim 5 ,
 wherein the solenoid actuator further includes a bracket that includes:
 a restrained portion that is restrained in the yoke to serve as the magnetic force transferring member; and 
 a fixed portion that externally secures the yoke, 
 
 the cup includes a collar portion that radially extends outwardly from an outer circumference of the cup, and 
 the collar portion is disposed on a side of the valve body axially with respect to the restrained portion. 
 
   
   
     7. The solenoid valve according to  claim 6 , wherein the stator is separated from the bracket. 
   
   
     8. The solenoid valve according to  claim 5 , wherein the stator, the yoke and the plunger form a magnetic circuit to magnetically attract the plunger.